20 



oontinuation of this work it was interesting to examine the leaves and 

 stem of the Rhus Metopium and 1 am much indebted to Mr. W. 

 Fawcett, Director of the Department of Public Gardens and Plantations, 

 Jamaica, for a very liberal supply of the raw material. 



To isolate the colouring matter an aqueous decoction of the leave* 

 was treated with lead acetate solution and the resulting pale yellow 

 precipitate containing the lead compound of the colouring matter, wa« 

 eoUected suspended in boiling water and decomposed with dilute sul- 

 phuric acid. The clear liquid was decanted from the lead sulphate, 

 agitated with ether, and the extract evaporated, a residue thus remain- 

 ing which consisted of the colouring matter containing el'acric and 

 gallic acids. After purification the colouring matter was obtained as 

 yellow needles soluble in dilute alkalis with a deep green colouration 

 and ap peared to be myricetin ; further experiment however indicated 

 the presence of two substances. Thus the acetyl compound prepared 

 in the usual manner had no definite melting point, and on analysis gave 

 numbers intermediate between those required by acetyl-quercetin and 

 acetyl-myricetin (0=57.25 ; H=4,51). [n order to separate the 

 mixe l colouring matters, the acetylised product obtained from them, 

 was fractionally crystallised from alcohol, a process suggested by th« 

 sparing solubility of acetyl myricetin in this solvent. The more insolu- 

 ble portion .vas eventually obtained as colourless needles melting at 

 204 ='-206 ^ . Analysis gave, 0=56.87 ; H=4.17. 



Ci5 H4 Os (O2 Hb Oe ) requires 0=56.84; H=a.86. 



It was apparently acetyl'myricetin, and to confirm this a portion 

 was converted into the free colouring matter by treatment with sul- 

 phuric acid and analysed 0=57.03 ; H=3.45. 



Oi5 Hio 08 requires 0=56.60 ; H=3.14. 



Thus obtained, the colouring matter formed glistening yellow needlet 

 having the dyeing properties and characteristic reactions of 

 myricetin. The amount contained in the leaves is approximately 1 

 per cent. The identification of the second colouring matter was difficult, 

 it being by tar the minor constituent of the mixture. By repeatedly 

 recrystaliising the more soluble portion remaining after the isolation of 

 the acetyl-myricetin, a fraction was obtained melting at 189^-191® 

 •iosely resembling acetyl-quercetin. On decomposition with sulphuric 

 acid this however yielded a colouring matter soluble in alkaline solution! 

 with a pale green colouration, indicating still a trace of myricetin, for 

 ^uercetin dissolves in this manner with a pale yellow tint. By the 

 action of bromine quercetin yields debrom-quercetin which is sparingly 

 loluble in alcohol, whereas myricetin thus forms a compound of a 

 readily soluble nature, and these reactions suggested a method for their 

 separation. The colouring matter as above purified was therefore 

 treated with bromine in the presence of glacial acetic acid, and the pro- 

 duct after standing twenty four hours crystallised from alcohol. It 

 consisted of yeliow needles melting at 237 '^-239 ® and was evidently 

 debrom-quercetin. A further confirmation of the presence of quercettn 

 in the mixed colouring matters was obtained by decomposing a trace 

 with fused alkali, when protocatechnic acid and phloroglucinol were 

 identified as present in the products of the reaction. Owing to the 

 ijoaall quantity contained in the leaves further tests could not be carried 

 oot. 



